An electromagnetic relay includes: a casing formed with an opening; a relay core member adapted for generating an electromagnetic field and inserted into the casing through the opening; an actuating set that is inserted into the relay core member, that is exposed from the casing, and that can be driven by a magnetic attraction force attributed to the electromagnetic field; a terminal set disposed on the casing and adapted to be actuated by the actuating set to thereby act as a switch mechanism; and a housing accommodating the casing, the relay core member, the actuating set and the terminal set.