81 West Lancaster Avenue
After escaping from the movie theater, several patrons headed across the street towards the Downingtown Diner. People eating in the diner saw what was going on decided that was not the best place to be at that moment. Jane's little brother attempted unsuccessfully to shoot The Blob with his toy gun and then ran inside. Jane and Steve followed him, only to become trapped as The Blob (now quite huge after many meals) enveloped the diner.
As The Blob begins to ooze in through the edges of the windows. Lt. Dave (Earl Rowe) sees the power wires running above the diner and decides to try electrocuting The Blob. He calls into the diner and tells Steve to get everyone down into the basement. When they get down there, they look out the window to see that The Blob has completely engulfed the building.
Currently, Chef Mcjon's Downingtown Diner resides on the site of the original Downingtown Diner.
Like Jerry's Market, there are conflicting stories about the Downingtown Diner. Some believe that the diner had undergone serious remodeling, with its exterior being drastically changed from how it looked in the film to its present appearance.
The Current owner, John DeLuca, tells a different story. The original diner as seen in The Blob, a Mahogany Car Model, was removed from the site around 1960, presumably sent out west to Hollywood to be used in motion pictures. In 1966 the current diner was placed on the site, a Silk City model manufactured by Paterson Vehicle Company of Paterson New Jersey. DeLuca claims that his diner (serial number 6671) was the last one to roll off the company’s construction line.
The basement has been left intact, whichever story is correct, but the small window at the right of the doorway has been blocked by a handicap ramp. Even though it's covered on the outside by a handicap ramp, the window that Steve and Jane eventually escaped through is still visible from inside.
The previous owner (who called it the Cadillac Diner) was happy to capitalize on The Blob theme, but disappointingly to fans, DeLuca is not following that tradition.
This is not to say that the new diner doesn’t have its own claim to cinematic fame, having been featured in the 2000 thriller Killer Instinct featuring Corbin Bernsen and Dee Wallace.
One important note. Unlike in the movie, the Colonial Theater and the Downingtown Diner location are about 18 miles apart. Or perhaps the movie-goers were all marathon runners!