A printer comprising: a paper path that guides paper used as a recording object through a predetermined path; a conveyance mechanism that in a predetermined direction, conveys the paper guided through the paper path; a sensor (603, 604) that includes a pair of sensor elements (607, 612) arranged to oppose each other across the paper path and to be movable along a direction orthogonal to a direction of conveyance of the paper by the conveyance mechanism; and a recording unit disposed on the paper path to perform a recording operation with respect to the paper conveyed through the paper path by the conveyance mechanism, based on a result of detection by the sensor (603, 604), wherein the printer further comprises a guide unit (701, 702) that forms a wave shape along the orthogonal direction and is formed on a frame (601, 602) supporting the conveyance mechanism and the recording unit, the sensor elements (607, 612) in the sensor (603, 604) are respectively interlinked with the guide unit (701, 702) via an elastic member (608, 613) biased in a direction to come into contact with the guide unit (701, 702), the elastic member (608, 613) elastically deforming according to the wave shape of the guide unit (701, 702), the sensor elements (607, 612) are disposed to be moveable along the guide unit (701, 702) by elastic deformation of the elastic member (608, 613) according to a position along the orthogonal direction, the guide unit (701, 702)for one sensor element (607, 612) of the sensor (603, 604) and the guide unit (701, 702) for another sensor element (607, 612) of the sensor (603, 604) respectively form the wave shape protruding and receding at same positions along the orthogonal direction. a paper path that guides paper used as a recording object through a predetermined path; a conveyance mechanism that in a predetermined direction, conveys the paper guided through the paper path; a sensor (603, 604) that includes a pair of sensor elements (607, 612) arranged to oppose each other across the paper path and to be movable along a direction orthogonal to a direction of conveyance of the paper by the conveyance mechanism; and a recording unit disposed on the paper path to perform a recording operation with respect to the paper conveyed through the paper path by the conveyance mechanism, based on a result of detection by the sensor (603, 604), wherein the printer further comprises a guide unit (701, 702) that forms a wave shape along the orthogonal direction and is formed on a frame (601, 602) supporting the conveyance mechanism and the recording unit, the sensor elements (607, 612) in the sensor (603, 604) are respectively interlinked with the guide unit (701, 702) via an elastic member (608, 613) biased in a direction to come into contact with the guide unit (701, 702), the elastic member (608, 613) elastically deforming according to the wave shape of the guide unit (701, 702), the sensor elements (607, 612) are disposed to be moveable along the guide unit (701, 702) by elastic deformation of the elastic member (608, 613) according to a position along the orthogonal direction, the guide unit (701, 702)for one sensor element (607, 612) of the sensor (603, 604) and the guide unit (701, 702) for another sensor element (607, 612) of the sensor (603, 604) respectively form the wave shape protruding and receding at same positions along the orthogonal direction.