A printer includes a frame that includes a frame back part, an open-close arm that includes an arm rotation shaft and is supported by the frame to rotate around the arm rotation shaft relative to the frame, a platen roller that is rotatably supported by the frame or the open-close arm, a print head that is disposed between the frame back part and the platen roller and performs printing on recording paper placed between the platen roller and the print head, and a first bias spring that is disposed between the frame back part and the print head and biases the print head toward the platen roller relative to the frame back part.
