A saddle-stitch and fold machine, comprising: a conveyer that is suitable for feeding a plurality of sheets one by one in a feed direction; a detector that is suitable for detecting a passage of a front end of the sheet fed from the conveyer so as to send a first detect signal; a creaser that is suitable for forming a crease on the sheet fed from the conveyer; a saddle-stitcher that is suitable for stacking the sheets fed from the creaser so as to make a sheet stack, and for saddle-stitching the sheet stack along the crease; a folder that is suitable for folding the sheet stack fed from the saddle-stitcher along the crease; a controller that is suitable for controlling the creaser, the saddle-stitcher and the folder; and an input device that is suitable for receiving input from an operator, wherein the creaser includes: a project part that is suitable for forming the crease on the sheet; and a receive part that is suitable for receiving the project part, wherein the project part can be moved between a crease position and a standby position, the project part forms the crease on the sheet when the project part is at the crease position, the project part does not form the crease on the sheet when the project part is away from the sheet at the standby position, wherein the input device includes a selector, the sheet to be creased by the creaser can be selected through the selector by the operator, the input device is suitable for sending select information on the sheet to be creased toward the controller, and wherein the controller is suitable for controlling the creaser based on both the select information from the input device and the first detect signal from the detector, whereby the sheet is creased by the project part disposed at the crease position when the sheet to be creased is fed from the conveyer toward the creaser; and the sheet is not creased by the project part disposed at the standby position when the sheet not to be creased is fed from the conveyer toward the creaser. a conveyer that is suitable for feeding a plurality of sheets one by one in a feed direction; a detector that is suitable for detecting a passage of a front end of the sheet fed from the conveyer so as to send a first detect signal; a creaser that is suitable for forming a crease on the sheet fed from the conveyer; a saddle-stitcher that is suitable for stacking the sheets fed from the creaser so as to make a sheet stack, and for saddle-stitching the sheet stack along the crease; a folder that is suitable for folding the sheet stack fed from the saddle-stitcher along the crease; a controller that is suitable for controlling the creaser, the saddle-stitcher and the folder; and an input device that is suitable for receiving input from an operator, wherein the creaser includes: a project part that is suitable for forming the crease on the sheet; and a receive part that is suitable for receiving the project part, wherein a project part that is suitable for forming the crease on the sheet; and a receive part that is suitable for receiving the project part, wherein the project part can be moved between a crease position and a standby position, the project part forms the crease on the sheet when the project part is at the crease position, the project part does not form the crease on the sheet when the project part is away from the sheet at the standby position, wherein the input device includes a selector, the sheet to be creased by the creaser can be selected through the selector by the operator, the input device is suitable for sending select information on the sheet to be creased toward the controller, and wherein the controller is suitable for controlling the creaser based on both the select information from the input device and the first detect signal from the detector, whereby the sheet is creased by the project part disposed at the crease position when the sheet to be creased is fed from the conveyer toward the creaser; and the sheet is not creased by the project part disposed at the standby position when the sheet not to be creased is fed from the conveyer toward the creaser. the sheet is creased by the project part disposed at the crease position when the sheet to be creased is fed from the conveyer toward the creaser; and the sheet is not creased by the project part disposed at the standby position when the sheet not to be creased is fed from the conveyer toward the creaser.