A cross-flow cooling fan device provided within electric appliances which require cooling, such as an audio amplifier, a microcomputer, a word processor or a copier. This device has a vane wheel, a metal bottom plate surrounding the bottom and rear portions of the vane wheel, a housing surrounding the front upper portion of the vane wheel, and a pair of end frames attached to both of the lengthwise end portions of these bottom plate and housing. The bottom plate and housing are provided at both of their respective lengthwise end portions with fitting members formed integrally therewith, and the end frames with receiving members in which the fitting members of the bottom plate and housing are fitted firmly, thereby forming a casing of the cross-flow cooling fan device.