[Object] To provide an operation apparatus capable of achieving an improvement in operability.[Solving Means] This operation apparatus includes: a casing including two surfaces opposed in front and back directions as a first surface and a second surface; a first operation input unit that is provided in the first surface and includes a detector that performs a detection of an operation of a user with respect to a predetermined coordinate detection space on the first surface; a second operation input unit provided in the second surface; a determination unit that determines an attitude of the casing when an operation of the user with respect to the coordinate detection space of the detector is performed from a side of the second surface; and a converter that converts, when the attitude is determined, information detected by the detector into information of a coordinate system of the coordinate detection space seen through from the side of the second surface.