The device has a line arrangement (2), which possesses an inlet (3) connectable to a supply line and an outlet (4) connectable to a shower arm (5). A heating element (6) serves for the provision of warm water. An energy store (7, 8) is provided, with which the power range for the provision of shower water can be extended. The heating element (6) for the provision of warm water is, in particular, a continuous-flow heater. The energy store (7, 8) is, in particular, a thermal, electrical, electrochemical or chemical energy store. During the shower process, the energy store is available as an additional energy source for the preparation of shower water.