Provided is an Al alloy film for semiconductor devices, which has excellent heat resistance and is suppressed in the generation of hillocks even in cases where the Al alloy film is exposed to high temperatures, and which has low electrical resistivity as a film. The present invention relates to an Al alloy film for semiconductor devices, which is characterized by satisfying all of the features (a)-(c) described below after being subjected to a heat treatment wherein the Al alloy film is held at 500° C. for 30 minutes and by having a film thickness from 500 nm to 5 μm. (a) The maximum grain diameter of the Al matrix is 800 nm or less. (b) The hillock density is less than 1×109 pieces/m2. (c) The electrical resistivity is 10 μΩcm or less.