The Stiegelbauer workshop, where Stephen DeMaria coordinated the construction of sets for “Saturday Night Live,” is in the Brooklyn Navy Yard, miles from 30 Rockefeller Plaza. Geographically, and in the minds of “S.N.L.” fans, DeMaria’s name was always far removed from the prestige and glamour of the show that has defined American comedy since 1975. But while most viewers have never heard of him, he has spent 50 years setting the scenes for the show’s most memorable moments.

And now he is done. DeMaria, known as “Demo” in the shop, retired after the 50th season finale, May 17. The day before, the white-haired, 87-year-old carpenter was leaning over his drafting table, inspecting blueprints and fiddling with the No. 2 pencil usually found behind his ear. For DeMaria and his crew, the show had already begun.

Stiegelbauer Associates Inc. is a cross between a shop class and a late-night museum: A Rainbow Room marquee hangs above a workbench; a leftover airplane set sits plastic-wrapped; photos of past sets installed in the show’s Studio 8H are framed on every wall.

During show weeks, sets are assembled all over the shop by an eclectic crew of craftspeople, many of whom have worked on “S.N.L.” for decades. As the foreman, DeMaria coordinates the teams assigned to build the sets designed at 30 Rock. Then he oversees the construction, moseying through the shop and kicking up sawdust with his cane as he checks in at the workstations.

The cane was the result of an injury he suffered at an end-of-season celebration last year: After a night of tearing up the dance floor, he fell off a curb and broke his hip.

“The best time of my life is the ‘S.N.L.’ parties,” he said. “I’ll be on the dance floor when I get there, and I won’t leave until 5 in the morning.” His favorite, he said, was the 2012 end-of-season party, after an episode hosted by Mick Jagger. “He was dancing all over the studio, so I got involved,” DeMaria recalled. “I was dancing with Mick Jagger!”