A portable freestanding stove designed to combust organic material pieces, having open combustion chamber (1) surrounded with sidewall (2) composed of one inverted truncated upper sheet metal cone (6) of combustion chamber (1) and surrounding thereof circumferential sheet metal ring (7) of combustion chamber (1). Positioned under upper cone (6) is second inverted truncated lower sheet metal cone (8) of air draft. Both truncated cones (6, 8) are rigidly positioned, one relative to the other, with axial gap (h) determined by means of circumferential sheet metal ring (7), rigidly connected to them and positioned at external circumference thereof. The lower part of upper cone (6) connects to grate (3), under which sheet metal ash pan (4) is positioned. Circumferential sheet metal ring (7) of stove rests on supporting structure (5).