To provide a container support base stably supporting a container such as a drink box in which the size of an opening part is not fixed, other than a plastic bottle.

The container support base includes a bar-like body 2 of a vertical posture to which the opening part 10a of an inverted container 10 is externally inserted to be supported with the bar-like body 2. The bar-like body 2 has: a longitudinal slit 2a having an opened upper end; and receiving parts 2c projected laterally. The receiving part 2c has a vertical slit 2c1 having an opened upper end. An outer periphery of the bar-like body 2 is provided with vertically long recess parts 2b extended from a position lower than the height of the upper end of the receiving part 2c to the upper end of the bar-like body 2, and a lower part of the bar-like body 2 has a sucking disk 3 which can be fixed to the other object. The drink box is supported by inserting a side wall of the opening part 11a of the inverted drink box 11 from above into the longitudinal slit 2a of the bar-like body 2. The plastic bottle is supported by inserting the opening of the inverted plastic bottle from above into the bar-like body 2.