X0508 4 2023-08-11 0 0000720500 AMTECH SYSTEMS INC ASYS 0001267540 DAIGLE ROBERT C C/O AMTECH SYSTEMS, INC. 131 S. CLARK DRIVE TEMPE AZ 85288 1 1 0 0 Chief Executive Officer 0 Amtech Systems, Inc. $0.01 par value common stock 2023-08-11 2023-08-11 4 P 0 15386 8.93 A 18470 D Amtech Systems, Inc. $0.01 par value common stock 2023-08-14 2023-08-14 4 P 0 1000 9.10 A 19470 D The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $8.60 to $9.00, inclusive. The reporting person undertakes to provide to Amtech Systems, Inc., any security holder of Amtech Systems, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnote 1 to this Form 4. /s/ Robert C. Daigle 2023-08-15