This guide describes how to use the STEP File Analyzer, a software tool that generates a spreadsheet from a STEP (ISO 10303 - informally known as the STandard for Exchange of Product model data) 1,2,3] file. The spreadsheets simplify inspecting information from the STEP file at an entity and attribute level. In this report a "STEP file" refers to a file that is exported by CAD (Computer-Aided Design) software in a format described by ISO 10303-21 4] and typically known as a Part 21 file.