An imaging apparatus for diagnosis comprising an imaging probe, an operation control apparatus and a motor drive apparatus having a transmitting and receiving unit which is configured to carry out continuous signal transmission and reception, the motor drive apparatus comprising: a scanner unit configured to axially rotate the transmitting and receiving unit, the scanner unit possessing opposite side surfaces each extending in a straight-ahead direction of the scanner unit; a pull-back unit configured to operate the scanner unit in a straight-ahead direction in order to axially move the transmitting and receiving unit in a body lumen, the pull-back unit possessing a forward end and an oppositely located rear end in the straight-ahead direction of the scanner unit, the pull-back unit also possessing a bottom surface; an operation unit comprising an instruction unit permitting instruction input to control the scanner unit and the pull-back unit, and an indicator indicating a state of the motor drive apparatus, the instruction unit and the indicator being aligned on a side surface of the pull-back unit; the operation unit being positioned only on one side surface of the pull-back unit; characterized in that said pull-back unit further comprises a portable mechanism for both hands comprising a shelf portion at the forward end of the pull-back unit on the side of the pull-back unit on which the operation unit is arranged and a shelf portion at the rear end of the pull-back unit on the side of the pull-back unit on which the operation unit is arranged; each of the shelf portions possessing an upper surface and also possessing a bottom surface spaced from the bottom surface of the pull-back unit so that a space exists on the lower side of each of the shelf portions; side wall portions surrounding each of the shelf portions, each side wall portion possessing an upper end portion higher than the upper surface of the shelf portion so that a concave portion or recessed portion is formed by the upper surface of the shelf portion and the encircling of the side wall portion; and the bottom surface of the pull-back unit at the forward end of the pull-back unit including a groove, and the bottom surface of the pull-back unit at the rear end of the pull-back unit including a groove, each groove extending for a predetermined length along the straight-ahead direction of the scanner unit, the grooves being located at an approximately center position relative to a direction perpendicular to the straight-ahead direction, wherein the shelf portion and the grooves are configured to permit a user to grasp one of the shelf portions together with one of the grooves using fingers of one hand of the user and to grasp the other shelf portion together with the other groove using fingers of the user's other hand. a scanner unit configured to axially rotate the transmitting and receiving unit, the scanner unit possessing opposite side surfaces each extending in a straight-ahead direction of the scanner unit; a pull-back unit configured to operate the scanner unit in a straight-ahead direction in order to axially move the transmitting and receiving unit in a body lumen, the pull-back unit possessing a forward end and an oppositely located rear end in the straight-ahead direction of the scanner unit, the pull-back unit also possessing a bottom surface; an operation unit comprising an instruction unit permitting instruction input to control the scanner unit and the pull-back unit, and an indicator indicating a state of the motor drive apparatus, the instruction unit and the indicator being aligned on a side surface of the pull-back unit; the operation unit being positioned only on one side surface of the pull-back unit; characterized in that said pull-back unit further comprises a portable mechanism for both hands comprising a shelf portion at the forward end of the pull-back unit on the side of the pull-back unit on which the operation unit is arranged and a shelf portion at the rear end of the pull-back unit on the side of the pull-back unit on which the operation unit is arranged; each of the shelf portions possessing an upper surface and also possessing a bottom surface spaced from the bottom surface of the pull-back unit so that a space exists on the lower side of each of the shelf portions; side wall portions surrounding each of the shelf portions, each side wall portion possessing an upper end portion higher than the upper surface of the shelf portion so that a concave portion or recessed portion is formed by the upper surface of the shelf portion and the encircling of the side wall portion; and the bottom surface of the pull-back unit at the forward end of the pull-back unit including a groove, and the bottom surface of the pull-back unit at the rear end of the pull-back unit including a groove, each groove extending for a predetermined length along the straight-ahead direction of the scanner unit, the grooves being located at an approximately center position relative to a direction perpendicular to the straight-ahead direction, wherein the shelf portion and the grooves are configured to permit a user to grasp one of the shelf portions together with one of the grooves using fingers of one hand of the user and to grasp the other shelf portion together with the other groove using fingers of the user's other hand.