An automatic powder collecting system, comprising: a powder collecting device including: a pipe for air intake and air supply including a connected part; and a plurality of powder collectors, which are used by being mounted to the pipe; an air intake device, which is connected to the pipe of the powder collecting device, and is configured to perform air intake; an air supply device, which is connected to the pipe of the powder collecting device, and is configured to perform air supply; and a robot device including a robot arm and a robot hand that are operated so as to perform at least work of collecting, moving, and discharging the powder with the powder collector being mounted through intermediation of the pipe of the powder collecting device, the powder collector including: a connecting part having an air passage to be connected to the pipe; a collecting part having an air passage in which powder is collected to be kept through use of a suction force caused by air intake from the pipe reaching the air passage of the collecting part through the air passage of the connecting part and from which the collected powder is discharged through use of a discharge force caused by air supply from the pipe; a relaying part having an air passage connecting the air passage of the connecting part and the air passage of the collecting part to each other; and a filter part, which is arranged at a predetermined position of the air passage of the collecting part and is configured to block passage of the powder to be collected, wherein the robot device is configured to cause the robot arm and the robot hand to hold the powder collector so that the collecting part is laid down substantially horizontally after the work of collecting the powder is finished and to perform the work of moving and discharging the powder while holding the powder collector under a state in which the collecting part is laid down substantially horizontally. a powder collecting device including: a pipe for air intake and air supply including a connected part; and a plurality of powder collectors, which are used by being mounted to the pipe; a pipe for air intake and air supply including a connected part; and a plurality of powder collectors, which are used by being mounted to the pipe; an air intake device, which is connected to the pipe of the powder collecting device, and is configured to perform air intake; an air supply device, which is connected to the pipe of the powder collecting device, and is configured to perform air supply; and a robot device including a robot arm and a robot hand that are operated so as to perform at least work of collecting, moving, and discharging the powder with the powder collector being mounted through intermediation of the pipe of the powder collecting device, the powder collector including: a connecting part having an air passage to be connected to the pipe; a collecting part having an air passage in which powder is collected to be kept through use of a suction force caused by air intake from the pipe reaching the air passage of the collecting part through the air passage of the connecting part and from which the collected powder is discharged through use of a discharge force caused by air supply from the pipe; a relaying part having an air passage connecting the air passage of the connecting part and the air passage of the collecting part to each other; and a filter part, which is arranged at a predetermined position of the air passage of the collecting part and is configured to block passage of the powder to be collected, a connecting part having an air passage to be connected to the pipe; a collecting part having an air passage in which powder is collected to be kept through use of a suction force caused by air intake from the pipe reaching the air passage of the collecting part through the air passage of the connecting part and from which the collected powder is discharged through use of a discharge force caused by air supply from the pipe; a relaying part having an air passage connecting the air passage of the connecting part and the air passage of the collecting part to each other; and a filter part, which is arranged at a predetermined position of the air passage of the collecting part and is configured to block passage of the powder to be collected, wherein the robot device is configured to cause the robot arm and the robot hand to hold the powder collector so that the collecting part is laid down substantially horizontally after the work of collecting the powder is finished and to perform the work of moving and discharging the powder while holding the powder collector under a state in which the collecting part is laid down substantially horizontally.