An image capturing device comprising: an elongate outer sheath; a vibrator or an image capturing unit disposed in the outer sheath; a drive shaft to which the vibrator or the image capturing unit is fixed at a distal portion thereof, the drive shaft configured to transmit drive power to the vibrator or the image capturing unit in the outer sheath; an inner sheath configured to be movable along a central axis of the outer sheath in the outer sheath, the drive shaft extending through the inner sheath; a first housing to which a proximal portion of the outer sheath is fixed, the drive shaft and the inner sheath extending through the first housing; a second housing that is disposed proximal to the first housing and to which a proximal portion of the inner sheath is fixed, the drive shaft being rotatably held in the second housing; a first gap between the inner sheath and the outer sheath; and a second gap between the inner sheath and the drive shaft, wherein the first housing includes a first port held in fluid communication with the first gap, the second housing is configured to be movable toward and away from the first housing and includes a second port held in fluid communication with the second gap, the vibrator or the image capturing unit is configured to be movable along the central axis of the outer sheath in the outer sheath with the inner sheath and the drive shaft, and the outer sheath includes a closed distal end, the vibrator or the image capturing unit is disposed distal of a distal end of the inner sheath, the first gap and the second gap are held in fluid communication with each other on the distal end of the inner sheath so as to allow a fluid to flow from the second port of the second housing to the closed distal end of the outer sheath through the second gap, and to flow from the closed distal end of the outer sheath to the first port of the first housing through the first gap. an elongate outer sheath; a vibrator or an image capturing unit disposed in the outer sheath; a drive shaft to which the vibrator or the image capturing unit is fixed at a distal portion thereof, the drive shaft configured to transmit drive power to the vibrator or the image capturing unit in the outer sheath; an inner sheath configured to be movable along a central axis of the outer sheath in the outer sheath, the drive shaft extending through the inner sheath; a first housing to which a proximal portion of the outer sheath is fixed, the drive shaft and the inner sheath extending through the first housing; a second housing that is disposed proximal to the first housing and to which a proximal portion of the inner sheath is fixed, the drive shaft being rotatably held in the second housing; a first gap between the inner sheath and the outer sheath; and a second gap between the inner sheath and the drive shaft, wherein the first housing includes a first port held in fluid communication with the first gap, the second housing is configured to be movable toward and away from the first housing and includes a second port held in fluid communication with the second gap, the vibrator or the image capturing unit is configured to be movable along the central axis of the outer sheath in the outer sheath with the inner sheath and the drive shaft, and the outer sheath includes a closed distal end, the vibrator or the image capturing unit is disposed distal of a distal end of the inner sheath, the first gap and the second gap are held in fluid communication with each other on the distal end of the inner sheath so as to allow a fluid to flow from the second port of the second housing to the closed distal end of the outer sheath through the second gap, and to flow from the closed distal end of the outer sheath to the first port of the first housing through the first gap.