A working machine support belt includes: a back plate portion; a left shoulder belt and a right shoulder belt; a waist belt; a left suspender band that connects the left shoulder belt and the waist belt; a right suspender band that connects the right shoulder belt and the waist belt; a left side belt that extends left-downward from the back plate portion, turns forward, and is connected to a left end portion of the waist belt; a right side belt that extends right-downward from the upper portion of the back plate portion, turns forward, and is connected to a right end portion of the waist belt; a locking member that locks the left end portion and the right end portion of the waist belt; and a pad member supported via a rear support band and a front support band, and provided with a hook that supports a working machine.