“The Last Schwartz” mines its material for every last laugh. And, for the most part, it hits pay dirt.

Playwright Deborah Zoe Laufer’s impressive debut offering at the Marin Theatre Company in Mill Valley is so entertaining it should keep audiences chuckling through an extension or two — especially if they are Jewish.

But is it a comedy? The themes of “The Last Schwartz” — infertility, alienation of family members, loss of faith, death and its aftermath — are as serious as they come. Add to that an autistic brother who is going blind, and what’s to laugh at?

Yet, laugh we do. Sometimes in recognition of situations and people we know all too well.

There’s the bossy, know-it-all older sister, Norma, played with autocratic skill and impeccable New York Jewish intonation by popular Bay Area actress Sharon Lockwood, who is almost unrecognizable in the role.

At once at odds with her and under her heavy thumb is Herb, the practical moneyman (Michael Tucker in a deft if somewhat over-the-top performance).

The adored baby brother, Gene (Darren Bridges), is a high-powered show-biz type who arrives late for the unveiling of his father’s headstone and with his latest bimbo, Kia (the delightful Megan Towle, who almost steals the show) in tow.

Most of all, there is Bonnie, Herb’s Jewish convert wife, frustrated in her attempts to have a child, fed up with her unresponsive husband, shut out by the rest of the family and lusting after her brother-in-law, Gene.

If Towle almost steals the show, Jill Eikenberry positively walks away with it. She and Tucker (real-life husband and wife, Mill Valley residents and famed for their long run in “L.A. Law”) play off each other with consummate skill, and it is a joy to watch. There is no doubt that real professionals are at work here.

The final family member is Simon (Mark Phillips), a near-blind astronomer who spends most of his time onstage (and he is onstage all of the time, almost like a piece of the well-worn furniture in the ancestral Schwartz home) peering through a telescope, “remembering” the star clusters he once was able to perceive.

Phillips does a fine job with the part, but it’s the character that is the problem. Every now and then, the action freezes and Simon stands in a spotlight to tell us his inner thoughts — mostly about the end of the world. Like, this is the meaningful part, folks, pay attention. And it doesn’t really work.

There is enough meaning in Bonnie’s pain and Norma’s alienation. In the losing of traditional values, the falling-apart of families and the dubious legacy of hurt that seems to be passed down from one generation to another.

Simon’s autism strikes a false note, enabling the author to toggle back and forth between the petty squabblings of siblings and the great mysteries of the universe. Better she should stick to the comedy.

They’ve all come together (a rare occasion, we are given to understand) to share a Shabbat dinner of brisket and chopped liver and observe the yahrzeit of the family patriarch. And, like at certain weddings, funerals and other obligatory functions, the worst eventually comes out in everybody.

And the best.

Eikenberry achieves a transformation from beaten-down outsider to heroine that is amazing, with wonderful support by a surprisingly sympathetic Towle.

Bonnie’s long scene of revelation and reconciliation with Kia, sharing a joint and a bottle of scotch, is at the heart of the second act. Neither of them is as dumb as the family supposes. They are possibly the most genuine people in the house.

The playwright and the director, Lee Sankowich, have taken all these ingredients and mixed them together into a delightful stew. Not totally gourmet, but it should keep audiences coming back for more.

“The Last Schwartz” runs through Sunday, Feb. 8 at Marin Theatre Company, 397 Miller Ave., Mill Valley. Tickets: $28-$45. Information: (415) 388-5208, www.marintheatre.org.