A mixing and thawing device (1) has a rocker drive (2) and a bag holder (3) for holding a bag (7). The bag holder (3) has a base part (8) and a lid part (9) that enclose a holding space (10) for the bag (7). A heating element (11) is arranged in the base part (8). Thus, the holding space (10) is designed as a heat-insulating closed chamber. Interconnected intermediate spaces (14, 15) are arranged between the bag (7) and the base part (8) and between the bag (7) and the lid part (9). One or more flow generators (16) are provided to generate a circulating fluid flow (17).