NEW YORK — Construction is under way in Brooklyn on a $19.5 million Jewish children's museum.

More than 400 people — among them New York Mayor Rudolph Giuliani and a who's who of other New York politicians — turned out for last week's groundbreaking of the Jewish Children's Museum, believed to be the first-ever institution of its kind.

While there are more than 400 children's museums in the United States and 80 Jewish museums, this will be the first large-scale institution to blend the two missions.

Scheduled to open in 2001, the museum will use technology and hands-on activities to teach Jewish history, values and traditions to the elementary school set. The museum, which is part of the Lubavitch movement, expects 120,000 visitors a year.

Museum planners have hired the architectural firm Gwathmey Siegel and Associates, which designed the Guggenheim Museum addition and the American Museum of the Moving Image.

Douglas J. Gallagher, a firm that did similar work for The Rock and Roll Hall of Fame in Cleveland and the Smithsonian Institution in Washington D.C., is designing the exhibits.

"In the beginning we thought of this as a much smaller project, but then we thought this has to be done in a way that ensures Jewish and non-Jewish people take this seriously," said Rabbi Yerachmiel Benjaminson, executive director of Tzvios Hashem, the Lubavitch children's organization responsible for developing the museum.

Among the more than 42 exhibits planned for the museum: a larger-than-life Shabbat dinner table that children can climb on, computer terminals that look like matzah balls, and a Tu B'Shevat exhibit in which children can scale trees and — by pulling fruit — activate stories and songs. The museum will also sponsor arts and crafts workshops on Jewish themes.

Although the museum is an offshoot of a Lubavitch-sponsored children's organization and will be located across the street from the world headquarters of the Lubavitch movement in Crown Heights, leaders say they are designing it to appeal to a broad spectrum of visitors.

Mindy Duitz, a museum consultant, interviewed staff at 20 Jewish day schools, afternoon Hebrew schools and camps, and spoke with another 80 individuals from different sectors of the Jewish community to find out what features might make them likely — or not likely — to attend.

She found concerns about proselytizing, gender discrimination and contents being "biased towards one perspective."

These are all issues the museum will address, Benjaminson said

"People should feel they're coming to a learning experience, not one saying you must do this or must do that," he said. "It's giving an enjoyable feeling of what Jewish traditions are all about. We've tried to stay away from anything controversial."

The museum will also welcome non-Jewish visitors and, according to its mission statement, provide "a setting for non-Jewish children to gain a positive perspective and awareness of the Jewish heritage, fostering tolerance and understanding."

Crown Heights is a working class, mixed-race neighborhood with a history of black-Jewish tensions that culminated in riots eight years ago.

But museum leaders say they are making efforts not just to ensure smooth relations but to present the museum as an instrument for promoting tolerance and understanding in the neighborhood.

"Crown Heights will become a model community where people will become inspired because here is communication and harmony," Benjaminson said at the groundbreaking.

Although the museum aims to reach beyond the Lubavitch community, the groundbreaking had a decidedly Orthodox flavor.

Men and women were seated in separate sections — both at the ceremony and at a lunch reception following it. A picture of the late Lubavitch rebbe, Rabbi Menachem Mendel Schneerson, hung prominently on the dais.

Almost all the speakers effusively praised Devorah Halberstam, the museum's director of foundation and government services and a vocal advocate since the project's inception.

The museum is dedicated to the memory of her son, Ari, a yeshiva student who was killed when a Lebanese immigrant opened fire on a van full of Lubavitch teens on the Brooklyn Bridge in 1994.