The document is a user's manual for Version 1.0 of EPA's Hazardous Air Pollutant Program (HAP-PRO), and was prepared to assist permit engineers in reviewing applications for control of air toxics by calculating the capital and annual costs for six volatile organic compound (VOC) and three particulate control devices, including selected engineering parameters, which may be used to help pinpoint errors in the engineering design. Calculations used by the program mirror those presented in the revised EPA handbook, Control Technologies for Hazardous Air Toxics. A secondary purpose of HAP-PRO is to generate lists of all facilities containing a specified pollutant in their emission streams or a specified type of emission stream (organic or inorganic vapors and particulates). HAP-PRO's features include context-sensitive help to assist in data input, a windowed environment to provide a referential trail of the user's actions, lookup tables containing the characteristics of many common pollutants, and the ability to select air toxics either from an alphabetical list or by SIC category. HAP-PRO runs on all IBM compatible personal computers and requires an MS-DOS Version 3.1 or greater, a hard disk with at least 1 megabyte free, and 512 K free minimum RAM.