Device of assistance for a user of a ladder, comprising a cable pulled by a controlled driving apparatus being laid in a loop along the height of the ladder, the user being attachable to said cable by a lanyard, a sensor means disposed in the driving apparatus allowing to detect movements of ascension or descent of the user along the ladder, a control means with a determined control program connected to the sensor means controlling the driving apparatus of the cable according to the movements of the user so that when the device is assisting the user, the driving apparatus drives the cable with determined assistance levels corresponding to pulling forces for the user which are lower than the force of gravity of the weight of said user, a remote control for activation or deactivation of the assistance characterized in that the remote control also allows manual input of the weight of the user, the remote control remaining in the reach of the user, the remote control being preferably attached to the lanyard, the remote control comprising a stop button for the deactivation of assistance, when deactivated no assistance being provided, and two activation buttons (14, 15) for the activation of the assistance, one for selecting "up" direction for when the person wants an assistance on climbing and one for selecting "down" direction for when the person wants an assistance on descent, and in that the device, comprises a memory for storage of sets of control values for the control of the assistance level(s) of the driving apparatus by the control means, the assistance level(s) for each direction of movement, up or down, corresponding to at most two levels in the steady state of the assistance, each set of control values being for a given weight of the user and having for an "up" direction selection two control values, a base control value for an "up" selection, a nominal control value for an "up" selection, the base control value giving a lower assistance level to the user than the nominal control value, the lower assistance level being not null, the program of the control means having material means for allowing: - the selection among the sets of the one that corresponds to the weight of the user entered in the control means with the remote control, - the activation which is only obtained by the activation buttons of the remote control, the activation buttons allowing the start of assistance to a level set to the base control value for the selected direction, - the deactivation which is obtained by either the stop button of the remote control, or by the detection by the sensor of no movements of the user, or by the detection by the sensor of an actual direction of movement of the person opposite to the activation button which was selected by the person. - the selection among the sets of the one that corresponds to the weight of the user entered in the control means with the remote control, - the activation which is only obtained by the activation buttons of the remote control, the activation buttons allowing the start of assistance to a level set to the base control value for the selected direction, - the deactivation which is obtained by either the stop button of the remote control, or by the detection by the sensor of no movements of the user, or by the detection by the sensor of an actual direction of movement of the person opposite to the activation button which was selected by the person.