Cellulose powder, having an average polymerization degree of 150-450, measured by the copper ethylene-diamine solution viscosity method described in the crystalline cellulose identification test in the 13 th revised Japanese Pharmacopoeia, an average L/D (the ratio of the major axis to the minor axis) value of particles of 75 μm or less that had passed through a 75-μm JIS standard screen, the L/D value being defined as the ratio between the long side and the short side, long side/short side, of a rectangle having the smallest area among rectangles circumscribed about the particle, wherein 400 particles which had been made discrete are used to determine the average L/D value, of 2.0 to 4.5, an average particle size of 20-250 μm, determined as follows: using a low-tap type sieve shaker and JIS standard screens Z8801-1987, 10 g of a powder sample was sieved for 10 minutes to measure the particle size distribution, wherein the average particle size is expressed as a particle size corresponding to a cumulative weight percentage of 50%, an apparent specific volume of 4.0 to 7.0 cm 3 /g, determined as follows: a powder sample was packed into a 100 cm 3 glass metering cylinder over a period of 2 - 3 minutes, and the top surface of the powder layer was made level with a soft brush, after which the volume of the powder sample was read, wherein the apparent specific volume is expressed as a value obtained by dividing the read value by the weight of the powder sample, and wherein the weight of the powder was determined so that it's volume was 70 - 100 cm 3, an apparent tapping specific volume of 2.4 to 4.5 cm 3 /g determined using a Powder Tester Model T-R, manufactured by Hosokawa Micron Corporation, by filling the powder in a 100 cm 3 cup, tapping 180 times and then dividing the volume of the cup by the weight of the powder layer remaining in the cup, and an angle of repose, expressed as the average of three measurements, of 55° or less, the angle of repose being determined using a Powder Tester Model T-R, mfd. by Hosokawa Micron Corporation, by making the powder fall under the conditions of a metal funnel made of a material incapable of generating static electricity with an orifice diameter of 0.8 cm, and of vibration graduation 1.5, after adjusting the water content of powder which is measured by means of an infrared moisture meter Model FD-220 mfd. by KETT Science Laboratory (1g, 105°C) to 3.5-4.5%, and then measuring the angles of two ridgelines, measurement distance 3°, of a heap formed by the powder, wherein the average polymerization degree is 5 to 300 higher than a level-off polymerization degree, said level-off polymerization degree being measured by a viscosity method (a copper ethylenediamine method) and being the average polymerization degree measured after hydrolysis under the conditions of 2.5 N hydrochloric acid, boiling temperature and 15 minutes, the cellulose powder being obtainable by a process comprising: i) hydrolyzing a natural cellulosic material to obtain a dispersion of cellulose having said average polymerization degree of 150-450 which is 5 to 300 higher than the level-off polymerization degree, ii) obtaining a cellulose dispersion wherein the average L/D value of particles capable of remaining on a 75- to 38-μm JIS standard screen before drying of the cellulose dispersion, the L/D value being defined as the ratio between the long side and the short side, long side/short side, of a rectangle having the smallest area among rectangles circumscribed about the particle, wherein 100 particles are used to determine the average L/D value, is 3.0 - 5.5, by conducting stirring during the hydrolysis reaction or in a subsequent step, and iii) drying the thus obtained cellulose dispersion. i) hydrolyzing a natural cellulosic material to obtain a dispersion of cellulose having said average polymerization degree of 150-450 which is 5 to 300 higher than the level-off polymerization degree, ii) obtaining a cellulose dispersion wherein the average L/D value of particles capable of remaining on a 75- to 38-μm JIS standard screen before drying of the cellulose dispersion, the L/D value being defined as the ratio between the long side and the short side, long side/short side, of a rectangle having the smallest area among rectangles circumscribed about the particle, wherein 100 particles are used to determine the average L/D value, is 3.0 - 5.5, by conducting stirring during the hydrolysis reaction or in a subsequent step, and iii) drying the thus obtained cellulose dispersion.