The devout Jews, dressed in their traditional black hats and long coats, shouted "Shabbes! Shabbes!"
- the Yiddish word for Sabbath - while banging against one of the door's of Intel's Jerusalem office.
Jerusalem police spokesman Shmuel Ben-Ruby said no violence was reported in the protest.
Religious Jews are forbidden to work on the Jewish Sabbath, and in recent months a core group of Israel's devout Jewish community
- known as the "ultra-Orthodox" - have become increasingly militant in enforcing a Saturday work ban.
Protests against Jerusalem's municipality for operating a parking lot on the Jewish Sabbath have taken place on a near-weekly basis for months, and another protest is expected on Saturday.
It is not clear what prompted the sudden protests against Intel, which Israeli media reports has operated on Saturday for years.
"We have always worked according o the company's needs. If the needs call for it, we work on Shabbat (the Jewish Sabbath) as well," said Intel Israel spokesman Kobi Becker, speaking to a local Israeli daily Ynet on Thursday.