A stack-type laundry treating apparatus comprising: an upper treating apparatus including: an upper cabinet defining an upper appearance of the laundry treating apparatus, and including an upper base; a drying drum rotatably disposed in the upper cabinet,; an upper driver disposed on the upper base for rotating the drying drum; and an air flow path for supplying and discharging air to and from the drying drum, and a lower treating apparatus including: a lower cabinet defining a lower appearance of the laundry treating apparatus and including a lower top panel on which the upper base is mounted; a tub disposed in the lower cabinet for storing washing-water; a washing drum disposed inside the tub; and a lower driver for rotating the washing drum, wherein a support protrusion is formed on a bottom portion of the upper base to support the upper cabinet with respect to the lower cabinet, wherein the upper cabinet has an upper side panel defining a side face of the upper treating apparatus, and the lower cabinet has a lower side panel defining a side face of the lower treating apparatus, wherein the support protrusion is interposed between the upper side panel and the lower side panel to support the upper treating apparatus, characterized in that: the upper base is made of a synthetic resin material; the upper side panel includes an upper horizontal bent portion horizontally extending from a bottom of the upper side panel to an inside of the upper treating apparatus; and the support protrusion is disposed inwardly of the upper horizontal bent portion. an upper treating apparatus including: an upper cabinet defining an upper appearance of the laundry treating apparatus, and including an upper base; a drying drum rotatably disposed in the upper cabinet,; an upper driver disposed on the upper base for rotating the drying drum; and an air flow path for supplying and discharging air to and from the drying drum, and an upper cabinet defining an upper appearance of the laundry treating apparatus, and including an upper base; a drying drum rotatably disposed in the upper cabinet,; an upper driver disposed on the upper base for rotating the drying drum; and an air flow path for supplying and discharging air to and from the drying drum, and a lower treating apparatus including: a lower cabinet defining a lower appearance of the laundry treating apparatus and including a lower top panel on which the upper base is mounted; a tub disposed in the lower cabinet for storing washing-water; a washing drum disposed inside the tub; and a lower driver for rotating the washing drum, a lower cabinet defining a lower appearance of the laundry treating apparatus and including a lower top panel on which the upper base is mounted; a tub disposed in the lower cabinet for storing washing-water; a washing drum disposed inside the tub; and a lower driver for rotating the washing drum, wherein a support protrusion is formed on a bottom portion of the upper base to support the upper cabinet with respect to the lower cabinet, wherein the upper cabinet has an upper side panel defining a side face of the upper treating apparatus, and the lower cabinet has a lower side panel defining a side face of the lower treating apparatus, wherein the support protrusion is interposed between the upper side panel and the lower side panel to support the upper treating apparatus, characterized in that: the upper base is made of a synthetic resin material; the upper side panel includes an upper horizontal bent portion horizontally extending from a bottom of the upper side panel to an inside of the upper treating apparatus; and the support protrusion is disposed inwardly of the upper horizontal bent portion. the upper base is made of a synthetic resin material; the upper side panel includes an upper horizontal bent portion horizontally extending from a bottom of the upper side panel to an inside of the upper treating apparatus; and the support protrusion is disposed inwardly of the upper horizontal bent portion.