The document describes a modified artificial immune system (MAIS) algorithm for solving the single row facility layout problem (SRFLP). The SRFLP involves arranging machines in a single row to minimize material handling costs. Existing artificial immune system (AIS) algorithms have slow convergence and weak stability. The proposed MAIS uses local search around memory antibodies to improve the AIS algorithm. Simulations show MAIS achieves better results than standard AIS. The MAIS is applied to three types of SRFLP - equal distance, zero distance, and different distance between machines. The objective is to minimize the total material handling cost.