Abstract: A warmer for medical treatment includes a heater including a resist pattern for generating heat on front and back surfaces of the heater, a partition and cover respectively disposed on the front and back surfaces of the heater to surround the heater, thereby forming a passage, through which a fluid flows, together with the heater. The warmer also includes a first connection part for introducing the fluid into the passage, a second connection part for discharging the fluid from the passage, a pore defined in the cover, a filter disposed on an inner surface of a portion of the cover in which the pore is defined, and an air discharger coupled to the cover to discharge air contained in the fluid through the filter and the pore.