To provide am opening and closing device for a concrete form capable of easily carrying out the mold opening work for a form with a core.

A form 1 is provided with side plate sections 3 and 4 and a core 5 disposed in the side plate sections 3 and 4. A lifting lever 9 is connected with the core 5. A core lifting mechanism 22 constituted of a cam mechanism for lifting and lowering the lifting lever 9 to lift and lower the core 5 is provided on a rotating body 10 and the lifting lever 9. A side plate mold opening mechanism 23 constituted of a cam mechanism for mold opening the side plate sections 3 and 4 is provided. A cam channel 17 of the side plate section mold opening mechanism 23 is formed on a disk section 15 provided with a rotor 10 integrally. When the rotor 10 is rotated and the core 5 is lifted and lowered by the core lifting mechanism 22, the side plate sections 3 and 4 are mold opened linking with the core lifting and lowering operation.