A probe comprising: a transceiving surface that has a greater length in a length direction than in a width direction; and an array of a plurality of ultrasonic elements provided on the transceiving surface; the probe adapted to emit ultrasonic waves to a surface to be inspected of an object to be inspected, the surface to be inspected facing the transceiving surface, while moving in the width direction; each of the ultrasonic elements being formed in a square shape and tilted by 45° with respect to the length direction; the array of ultrasonic elements including first ultrasonic elements being arranged in the length direction and in a center of the length in the width direction, and second ultrasonic elements arranged on both sides in the width direction with being adjacent to the first ultrasonic elements arranged in the center of the width direction, and the probe is adapted to emit, the ultrasonic waves from an emission unit (S1,S2,S3) which includes one first ultrasonic element arranged in the center of the length in the width direction and four second ultrasonic elements adjacent to the four sides of the one first ultrasonic element while shifting the emission unit (S1,S2,S3) by one ultrasonic element in the length direction, so as to emit the ultrasonic waves twice in a row from each of the second ultrasonic elements arranged on both sides of the transceiving surface in the width direction except the second ultrasonic elements arranged on both side ends of the transceiving surface in the length direction and to emit the ultrasonic waves only once from each of the first ultrasonic elements arranged in the center of the length in the width direction. a transceiving surface that has a greater length in a length direction than in a width direction; and an array of a plurality of ultrasonic elements provided on the transceiving surface; the probe adapted to emit ultrasonic waves to a surface to be inspected of an object to be inspected, the surface to be inspected facing the transceiving surface, while moving in the width direction; each of the ultrasonic elements being formed in a square shape and tilted by 45° with respect to the length direction; the array of ultrasonic elements including first ultrasonic elements being arranged in the length direction and in a center of the length in the width direction, and second ultrasonic elements arranged on both sides in the width direction with being adjacent to the first ultrasonic elements arranged in the center of the width direction, and the probe is adapted to emit, the ultrasonic waves from an emission unit (S1,S2,S3) which includes one first ultrasonic element arranged in the center of the length in the width direction and four second ultrasonic elements adjacent to the four sides of the one first ultrasonic element while shifting the emission unit (S1,S2,S3) by one ultrasonic element in the length direction, so as to emit the ultrasonic waves twice in a row from each of the second ultrasonic elements arranged on both sides of the transceiving surface in the width direction except the second ultrasonic elements arranged on both side ends of the transceiving surface in the length direction and to emit the ultrasonic waves only once from each of the first ultrasonic elements arranged in the center of the length in the width direction.