A conveyance device includes a conveyance roller, a registration roller, a sensor, a mode setting part, a storage, a conveyance state determination part and a drive control part. The mode setting part sets the mode to either a plain paper mode or a tab paper mode. The storage stores threshold information corresponding to the mode. The conveyance state determination part determines, when the plain paper mode is set, whether the conveyance state of the recording medium is a skew conveyance state or a tab paper conveyance state, based on the detection result of the sensor and the plain paper mode threshold information. The conveyance state determination part determines, when the tab paper mode is set, whether the conveyance state of the recording medium is the skew conveyance state or the tab paper conveyance state, based on the detection result of the sensor and the tab paper mode threshold information.