To provide a multicylinder auxiliary chamber type engine, in which maintenance of parts disposed to an auxiliary chamber is safely performed, while continuing operation.

The auxiliary chamber type engine 100 is constituted by arranging a plurality of cylinders 1 in parallel with each other with respect to a crankshaft 16, in which each cylinder 1 is constituted of a main chamber 10 facing a piston 2 and the auxiliary chamber 11 communicating with the main chamber 10 through a communication passage 20. Each of the plurality of cylinder 1 is provided with a communication passage closing valve 30 which can maintain a closed state of the communication passage 20.