The objectives of this study were to develop and evaluate a solar dryer for drying by solar energy, determination of the optimum conditions for the solar dryer during the drying process of mango slices, okra slices and mint and comparing the cost of the solar dryer and drying on trays by direct sun . Two experimental groups were carried out for each crop. Every group consists of 9 treatments. The first group of tests was run under different number of trays 4, 5, and 7 trays with different product masses. The second group of tests was run under different number of open holes 5, 7, and 9 holes also with different product masses. It was lower cost for the drying products with obtain to suitable moisture content is (759.9, 934.8 and 1900.6) L.E/Mg under seven open slots, and four trays. In order to minimize drying cost, it is recommended to use the manufactured solar dryer for drying by solar energy for drying mango slices, okra slices and mint under the following conditions: Number of trays of (5 trays), number of open holes of (7 holes) and Mass of product of (1.25, 1.00 and 0.30 kg/tray) with okra, mango and mint, respectively.