A pilot-controlled electromagnetic valve is capable of preventing tilting of a piston and of shortening the piston with a simplified arrangement and allows a main valve element to be moved by actuation of a manual controller by transmitting the motion of the manual controller to both the piston and the main valve element. A partition is formed between a piston chamber and a manual controller chamber. A guide hole is formed in the partition. A guide projection is formed on the left side of the piston. The guide projection is inserted through the guide hole to project into the manual controller chamber. The manual controller having a sloped surface is reciprocatably provided in the manual controller chamber. Actuation of the manual controller causes the sloped surface to contact the sloped portion of the guide projection, thereby enabling both the piston and the main valve element to be moved.