To always obtain dust reduction effects at a certain high level by suppressing the change with time of the flowability of concrete after mixing, and thereby stabilizing spray conditions for a dust reduction agent for wet spray concrete.

The dust reduction agent for the wet spray concrete contains a water-soluble cellulose ether and a polyethylene oxide. The dust reduction agent is characterized in that a particulate polyethylene oxide containing particles having particle diameters of ≤150 μm in an amount of ≥70 wt.%, preferably particles having particle diameters of ≤250 μm in an amount of ≥90 wt.% is used.