In a vertical-type semiconductor device, a method of manufacturing the same and a method of operating the same, the vertical-type semiconductor device includes a single-crystalline semiconductor pattern having a pillar shape provided on a substrate, a gate surrounding sidewalls of the single-crystalline semiconductor pattern and having an upper surface lower than an upper surface of the single-crystalline semiconductor pattern, a mask pattern formed on the upper surface of the gate, the mask pattern having an upper surface coplanar with the upper surface of the single-crystalline semiconductor pattern, a first impurity region in the substrate under the single-crystalline semiconductor pattern, and a second impurity region under the upper surface of the single-crystalline semiconductor pattern. The vertical-type pillar transistor formed in the single-crystalline semiconductor pattern may provide excellent electrical properties. The mask pattern is not provided on the upper surface of the single-crystalline semiconductor pattern in the second impurity region, to thereby reduce failures of processes.