Provided is an operation input device including a base member; a grip that is gripped by an operator and that is moved relative to the base member; a coupling portion that couples the grip to the base portion in a pivotable manner; and a scaling-ratio changing mechanism that changes an amount by which the grip is moved with respect to a pivoting angle of the coupling portion, and an object thereof is to enable switching operation between a coarse movement and a fine movement by using the same operation.