PURPOSE: To prepare a deoxygenating agent with high deoxigenating activity commercially advantageously by a method wherein a fine powder of a porous filler and a coarse powder thereof are mixed in a specified ratio and, thereafter, a component contg. water and a metallic fine powder are mixed therewith at a constant ratio.

CONSTITUTION: A fine powder of a porous filler with particle size of 100 mesh or less and a coarse powder thereof with 100 mesh or more are prepared and, after water is added to said coarse powder in such a ratio that a total moisture content based on the total amount of both powders is 20W90% of a saturated water absorbing amount, 20W60vol% of the fine powder and 80W40vol% of the coarse powder are mixed. Subsequently, to this mixture, a metallic fine powder with a particle size of 100 mesh or less having deoxigenating activity is blended in such a volume ratio of 1/2W1/10 metallic powder/filler. The obtained deoxigenating product is uniform in quality and has high activity.