A direct liquid feed fuel cell system that includes a housing, a fuel cell stack in which air flow channels are formed, in the housing; and a fan that supplies air between the housing and a part of the air flow channels, wherein the fuel cell stack is obliquely mounted toward the fan. The fuel cell system can be arranged so that the airflow channels are substantially vertical, in order for air to be supplied between the housing and an upper part of the airflow channels, with the fuel cell stack downwardly obliquely mounted toward the fan. Furthermore, an outlet in the housing on an opposite side of the fuel cell stack from the fan can allow air that has passed through the air flow channels to be exhausted from the fuel cell system after passing through a space between a part of the fuel cell stack and the housing.