One of the basic functions of a porter robot is to recognize and to follow its user autonomously. Though various studies has been performed, a remaining common problem is to keep recognition of the user steady. Previously, the authors have examined such a user recognition and following method using an RGB-D camera and the well-known "skeleton tracking" function. As a result, shortcomings have been clarified such as the recognition can be lost easier in a short range, which make it hard for the robot to pass around a blind corner following its user. Thus, in this report, the authors newly examine a user recognition and following method using the "user tracking" function of an RGB-D camera which is known to be simpler but faster and more robust. First, the validity of the scheme is studied through experiments where the robot is to follow its user that moves straightly. Secondly, a camera-panning mechanism is introduced to enable the robot to pass around a blind corner not losing sight of its user and avoiding collisions to walls. A prototype panning mechanism is fabricated using a 3D printer, simple algorithms are implemented to realize a panning-to-follow function, and experiments are carried out to show feasibility of the proposed scheme.