To control a release period of a communication port by a poppet valve, to feed EGR gas and gas fuel to intake air, to prevent the occurrence of knocking by cooling gas fuel in a subsidiary chamber, to prevent the generation of NOx, and to improve thermal efficiency.

This divided gas engine has a poppet valve 5 driven by an electromagnetic force generated by an electromagnetic force drive device 35 controlled by a controller 40. The electromagnetic force drive device 35 comprises a magnetic plate 65 fixed at the poppet valve 5; an electromagnet 61 positioned opposite to the magnetic plate 65 and fixed at a cylinder head 3; a return spring 63 arranged between the magnetic plate 65 and the cylinder head 3 and energizing the poppet valve 5 in a direction in which a communication port 6 is closed; and a magnetic passage pipe 64 arranged outside the electromagnet 61 and the magnetic plate 65.