A freely movable apparatus (3) and an ultrasonic apparatus. The freely movable apparatus (3) has a first moving element (33) and a second moving element (34). The first moving element (33) and the second moving element (34) are disposed to be rotatable on a support element (31). When a user applies a force on a connecting base (39) or connecting arms (35, 36), the positions of the first moving element (33) and the second moving element (34) on the support element (31) can be changed, such that the first moving element (33) and the second moving element (34) can rotate, according to the applied force, by different angles or move away from each other or move towards each other on the support element (31) The angles between the connecting arms (35, 36) and the connecting base (39) and between the connecting arms (35, 36) and the moving elements (33, 34) can vary according to the applied force, such that the connecting base (39) can move and rotate to multiple positions in a plane. The structure can realize free multidirectional movement in a horizontal plane and is simple, such that the compactness and linkage flexibility of an apparatus are improved.L'invention concerne un appareil librement mobile (3) et un appareil à ultrasons L'appareil librement mobile (3) a un premier élément mobile (33) et un second élément mobile (34). Le premier élément mobile (33) et le second élément mobile (34) sont disposés de façon à pouvoir tourner sur un élément de support (31). Lorsqu'un utilisateur applique une force sur une base de liaison (39) ou des bras de liaison (35, 36), les positions du premier élément mobile (33) et du second élément mobile (34) sur l'élément de support (31) peuvent être changées, de telle sorte que le premier élément mobile (33) et le second élément mobile (34) peuvent tourner, selon la force appliquée, par différents angles ou s'éloigner l'un de l'autre ou se déplacer l'un vers l'autre sur l'élément de support (31). Les angles entre les bras de liaison (35,
