Intake air flow detecting device for internal combustion engine

An intake air flow detecting device is provided to an intake air passage, through which intake air flows into an internal combustion engine. Intake air flow is divided into a main passage and a bypass passage. The detecting device includes a thermal air flowmeter, a bypass flow delay information calculating means, and a response delay compensating means. The thermal air flowmeter includes a detector arranged in the bypass passage for detecting an air flow amount in the intake air passage. The bypass flow delay information calculating means calculates a bypass flow delay information representing delay in variation in a flow amount in the bypass passage with respect to variation in a flow amount in the main passage. The response delay compensating means compensates delay in response of the air flowmeter in accordance with the bypass flow delay information.