Abstract: An insecticide having high insecticidal activities against various harmful insects, which is low in toxicity to warm-blooded animals and fishes to be used safely. The insecticide comprises a derivative of 2,3-dihydro-2,2-dimethylbenzofuran-7-yl N-(substituted sulfonylcarbamoyl)-N-methylcarbamate represented by the general formula: ##STR1## wherein X stands for a halogen atom; --NHR where R is an alkyl group, cycloalkyl group, lower alkenyl group, lower alkynyl group or ##STR2## (where Z is a hydrogen atom, halogen atom, alkyl group, alkoxy group or alkoxycarbonyl group), aralkyl group, a 5-member or 6-member heterocyclic group, or an alkoxy group.