With the object of suppressing unintended motion of a slave device(4) due to an erroneous operation of a master device(2), the present invention provides an operation input device(2) including: a one-dimensional operation unit(22) which can generate a one-dimensional motion command signal; and a two-dimensional operation unit(23) which can generate a two-dimensional motion command signal, wherein the one-dimensional operation unit(22) and the two-dimensional operation unit(23) can be operated independently from each other.