The present invention provides a control agent for a plant pest and/or a plant disease, the control agent being environmentally friendly and having a high control effect. The control agent is a control agent for a plant pest and/or a plant disease, containing a polyglycerin fatty acid ester as an active ingredient. The polyglycerin fatty acid ester is an ester of at least one fatty acid selected from fatty acids having 8 to 10 carbon atoms, and at least one polyglycerin obtained by polymerizing 3 to 10 glycerins.
