A pipe processing device including a subject insertion body, which is insertable into a pipe from an opening portion of the pipe, to be movable in an axial direction along a center axis of the subject insertion body, a radial direction perpendicular to the center axis, a rotation direction of rotating about the center axis, and an oblique direction oblique with respect to the center axis, the pipe processing device comprising: a movement mechanism for moving the subject insertion body; a plurality of sensor support portions that are provided on the side portion of the subject insertion body and in which a plurality of inspection ultrasonic sensors for transmitting and receiving a sonic wave in the radial direction is disposed in the axial direction of the center axis, wherein the plurality of the sensor support portions is provided at symmetrical positions about the center axis and the plurality of the sensor support portions is supported to be slidable in a radial direction perpendicular to the center axis and is elastically biased in the radial direction; a plurality of protrusion portions provided to protrude on the side portion of the subject insertion body, wherein the plurality of protrusion portions is provided at symmetrical positions about the center axis, is supported to be slidable in the radial direction perpendicular to the center axis, and is elastically biased in the radial direction; an insertion end portion that is provided on a front side of the subject insertion body to be inserted into the pipe and is formed in a smaller outer diameter than an inner diameter of the pipe; an axial ultrasonic sensor for transmitting and receiving a sonic wave in an insertion direction with respect to a front end of the insertion end portion; a radial ultrasonic sensor for transmitting and receiving a sonic wave in the radial direction at a side portion of the insertion end portion; and a control unit for controlling the movement mechanism according to detection results of the axial ultrasonic sensor and the radial ultrasonic sensor, wherein the axial ultrasonic sensor is configured to detect a distance from an outer edge of an opening portion of the pipe in order to recognize a position of the pipe processing device with respect to the outer edge of the opening portion of the pipe, and the radial ultrasonic sensor is configured to detect a distance from an inner face of the pipe, characterized in that the protrusion portions are equally disposed in the radial direction based on the center axis with the sensor support portions. a movement mechanism for moving the subject insertion body; a plurality of sensor support portions that are provided on the side portion of the subject insertion body and in which a plurality of inspection ultrasonic sensors for transmitting and receiving a sonic wave in the radial direction is disposed in the axial direction of the center axis, wherein the plurality of the sensor support portions is provided at symmetrical positions about the center axis and the plurality of the sensor support portions is supported to be slidable in a radial direction perpendicular to the center axis and is elastically biased in the radial direction; a plurality of protrusion portions provided to protrude on the side portion of the subject insertion body, wherein the plurality of protrusion portions is provided at symmetrical positions about the center axis, is supported to be slidable in the radial direction perpendicular to the center axis, and is elastically biased in the radial direction; an insertion end portion that is provided on a front side of the subject insertion body to be inserted into the pipe and is formed in a smaller outer diameter than an inner diameter of the pipe; an axial ultrasonic sensor for transmitting and receiving a sonic wave in an insertion direction with respect to a front end of the insertion end portion; a radial ultrasonic sensor for transmitting and receiving a sonic wave in the radial direction at a side portion of the insertion end portion; and a control unit for controlling the movement mechanism according to detection results of the axial ultrasonic sensor and the radial ultrasonic sensor, wherein the axial ultrasonic sensor is configured to detect a distance from an outer edge of an opening portion of the pipe in order to recognize a position of the pipe processing device with respect to the outer edge of the opening portion of the pipe, and the radial ultrasonic sensor is configured to detect a distance from an inner face of the pipe, characterized in that the protrusion portions are equally disposed in the radial direction based on the center axis with the sensor support portions.