A filter device, comprising a housing having a top plate, a bottom plate for facing a floor, front and back plates (15, 13) and, and side plates to define a space inside the housing, the bottom plate having a bottom inlet, wherein the space in the housing is separated into a primary space and a secondary space (22, 24), and the housing is configured to allow air in the primary space to flow through a front of the housing;a filter frame provided over the bottom inlet and having at least one partition to provide a plurality of passage openings; wherein the filter frame is provided at a bottom of the primary space and configured to be drawn in and out of the housing, the bottom inlet of the housing allowing air be drawn into the primary space, and wherein at least one of the passage openings corresponds to a location of the bottom inlet and is a positioned over the bottom inlet; a first filter configured to filter air by being seated in the passage openings; and a second filter stacked on the first filter and further filtering the air, wherein a first surface of the first filter faces the floor and the second surface opposite of the first surface faces toward the space of the housing, legs, at at least four corners of the housing, having a predetermined height, being capable of contacting with the floor and thereby providing a space between a lower surface of the bottom plate and the floor, in which air can be sucked into the bottom inlet wherein the filter device further comprises: at least one fan being provided inside the secondary space (22, 24), the at least one fan being configured to pop-up above or retract from an upper surface of the housing. a housing having a top plate, a bottom plate for facing a floor, front and back plates (15, 13) and, and side plates to define a space inside the housing, the bottom plate having a bottom inlet, wherein the space in the housing is separated into a primary space and a secondary space (22, 24), and the housing is configured to allow air in the primary space to flow through a front of the housing;a filter frame provided over the bottom inlet and having at least one partition to provide a plurality of passage openings; wherein the filter frame is provided at a bottom of the primary space and configured to be drawn in and out of the housing, the bottom inlet of the housing allowing air be drawn into the primary space, and wherein at least one of the passage openings corresponds to a location of the bottom inlet and is a positioned over the bottom inlet; a first filter configured to filter air by being seated in the passage openings; and a second filter stacked on the first filter and further filtering the air, wherein a first surface of the first filter faces the floor and the second surface opposite of the first surface faces toward the space of the housing, legs, at at least four corners of the housing, having a predetermined height, being capable of contacting with the floor and thereby providing a space between a lower surface of the bottom plate and the floor, in which air can be sucked into the bottom inlet wherein the filter device further comprises: at least one fan being provided inside the secondary space (22, 24), the at least one fan being configured to pop-up above or retract from an upper surface of the housing.