The refrigerator may comprise: a first tray assembly forming a part of ice-making cells; and a second tray assembly forming the other part of the ice-making cells. In order that ice can be produced in the direction of ice-making cells formed by any One of the first and second tray assemblies to ice-making cells formed by the other tray assembly, following the start of an ice-making process, the one tray assembly comprises a first part, and the first part comprises: a first surface forming a part of the ice-making cells; and a first deformation-resistant reinforcement part extending from the first surface in the vertical direction away from a heater.