A medical adsorbent comprising spherical activated carbon which is activated carbon obtained by carbonizing and activating a spherical phenol resin and which has (a) an area to weight ratio of 800-2000 m2/g, (b) a pore volume of 0.2-1.0 mL/g, (c) a packing density of 0.5-0.75 g/mL, (d) a mean pore diameter of 1.7-2.0 nm, (e) a maximum particle size of no greater than 425 μm and a mean particle size of no greater than 350 μm, and (f) an overall pore volume of no greater than 0.04 mL/g of pores with pore diameters of 20-1000 nm, wherein the overall pore volume of pores with a mean pore diameter of no greater than 1.0 nm constitutes at least 55% of the total pore volume.