Abstract: In mounting an engine (vertical crankshaft internal combustion engine) to a frame (support) through a plurality of vibro-isolating members, at least one vibro-isolating member is a vibro-isolating member which is disposed at a position where the tension and rotating torque of a belt wound around an output pulley are substantially perpendicular to each other, or a vibro-isolating member disposed on a flat surface which includes an output shaft therein and is in parallel to the tension. Alternatively, the vibro-isolating members are disposed symmetrically through a flat surface which is in parallel to the output shaft and the tension of the belt and includes therein the center of gravity, or at least one vibro-isolating member is disposed on the flat surface. Also, an axis of the vibro-isolating members is oriented to correspond to a direction of the rotating torque.