A pills counting device is provided. It comprises a tray comprising a base member and a trough member. The device also comprises a lid member mounted on the base member and being movable between two extreme positions. The device also comprises at least one port provided in the tray and/or in the lid member and adapted to be connected in fluid communication with the base member and with an air intake of a vacuum device that can be remotely controlled. When a vacuum is applied to the at least one port, an air stream is established to entrain toward the vacuum device particles that may be present on surfaces of the device. A cleaning method using the aforesaid pills counting device is also disclosed.