A particle therapy system comprising: an accelerator that generates a charged particle beam; an irradiation nozzle used for irradiation of the charged particle beam; a treatment bed arranged in a tip direction of the irradiation nozzle and constructed movably; a treatment information system that manages prescription data; a treatment control system that receives a target position stored in the treatment information system to cause a main display system to present the target position; an irradiation control system that receives control parameters of the irradiation nozzle from the treatment control system to perform the control parameters; a pendant to input a movement command for the treatment bed wherein the pendant includes a display unit; a patient positioning system that controls the treatment bed based on the movement command; the main display system that receives the target position of the treatment bed from the treatment control system and displays an actual position of the treatment bed; and a patient positioning support system that calculates correction values for the target position of the treatment bed to provide the correction values to the treatment control system and the pendant, wherein the treatment control system sends the target position of the treatment bed to the treatment information system at a period shorter than an operation sequence of the treatment control system and stores initial values to be sent in advance, wherein the transmission of the target position of the treatment bed from the treatment control system to the treatment information system is started at fixed periods, characterized in that the pendant is arranged in a treatment room and the main display system is provided in an operation room next to the treatment room; the treatment control system periodically transmits initial values registered in advance to the treatment information system until correction values sent from the patient positioning system are received after the target position contained in the prescription data being sent to the main display system and after the correction values are received, instead of the initial values, the correction values are transmitted to the treatment information system; and wherein the treatment information system sends update information of the target position to the treatment control system and updates a display of the main display system when the target position transmitted from the treatment control system is within an operation range of the treatment bed and does not send the update information of the target position to the treatment control system when the target position transmitted from the treatment control system is not within the operation range of the treatment bed. an accelerator that generates a charged particle beam; an irradiation nozzle used for irradiation of the charged particle beam; a treatment bed arranged in a tip direction of the irradiation nozzle and constructed movably; a treatment information system that manages prescription data; a treatment control system that receives a target position stored in the treatment information system to cause a main display system to present the target position; an irradiation control system that receives control parameters of the irradiation nozzle from the treatment control system to perform the control parameters; a pendant to input a movement command for the treatment bed wherein the pendant includes a display unit; a patient positioning system that controls the treatment bed based on the movement command; the main display system that receives the target position of the treatment bed from the treatment control system and displays an actual position of the treatment bed; and a patient positioning support system that calculates correction values for the target position of the treatment bed to provide the correction values to the treatment control system and the pendant, wherein the treatment control system sends the target position of the treatment bed to the treatment information system at a period shorter than an operation sequence of the treatment control system and stores initial values to be sent in advance, wherein the transmission of the target position of the treatment bed from the treatment control system to the treatment information system is started at fixed periods, characterized in that the pendant is arranged in a treatment room and the main display system is provided in an operation room next to the treatment room; the treatment control system periodically transmits initial values registered in advance to the treatment information system until correction values sent from the patient positioning system are received after the target position contained in the prescription data being sent to the main display system and after the correction values are received, instead of the initial values, the correction values are transmitted to the treatment information system; and wherein the treatment information system sends update information of the target position to the treatment control system and updates a display of the main display system when the target position transmitted from the treatment control system is within an operation range of the treatment bed and does not send the update information of the target position to the treatment control system when the target position transmitted from the treatment control system is not within the operation range of the treatment bed.