OPPOSED-PISTON ENGINE

Provided is an opposed-piston engine which enhances thermal efficiency by improving heat insulation efficiency of constitutional members of the engine as much as possible, realizing a high compression ratio in a combustion chamber and lowers vibrations. Left and right pistons which are movable independently from each other are housed in the inside of a horizontal cylinder in a state where heads of the respective left and right pistons face each other in an opposed manner, one combustion chamber is formed outside the horizontal cylinder in a state where the combustion chamber is communicated with a space defined between the left and right piston heads whereby an output is taken out by making use of approaching each other or moving away from each other of the left and right pistons caused by ignition explosion in the inside of the combustion chamber.