To ensure safety in the case of going up and down a ladder so as to enable an operator to easily get in and out even at night.

A handrail part 33 of a ladder 30 provided to go up to and down from a fender is provided with an elevating unit 50 fitted with an article storage box for taking up and down tools or the like, and a lamp for illuminating feet. The elevating unit 50 has a slider 51 that can self-advance along either one of the lateral handrail parts 33. An electric motor 53 is fitted to the slider 51, and an output shaft of the electric motor 53 is connectedly provided with a pinion 54. The pinion 54 is meshed with a rack 52 of the handrail part 33, and when the electric motor 53 is driven to rotate the pinion 54 the slider 51 is elevatingly displaced along the handrail part 33. The slider 51 is detachably mounted with a lamp unit 70, the article storage box 81, and the like.