A method for determining an exposure condition for use in projecting an image of a pattern of an original on a substrate includes a setting step of setting an exposure condition, an image calculating step of calculating a dimension of an image to be projected on the substrate under the set exposure condition, an electrical characteristic calculating step of calculating an electrical characteristic of at least one of a portion for use as an interconnection and a portion for use as a transistor in a pattern to be formed on the substrate in accordance with a result calculated in the image calculating step, a determining step of determining whether the electrical characteristic calculated in the electrical characteristic calculating step satisfies a requirement, and an adjusting step of adjusting the set exposure condition when the electrical characteristic is determined not to satisfy the requirement in the determining step.