A method for monitoring the environment of a robot including at least one iteration of a detection phase including the following steps:—acquisition, at a measurement instant, of an image of the depth of the environment, referred to as a measurement image, by the at least one 3D camera,—readjustment of the reference and measurement images, and—detection of a change relating to an object in the environment of the robot by comparing the reference and measurement images. A device that implements such a method and a robot equipped with such a device is also provided.