This book "Microstrip Band Stop Filters" is written to cater the needs of the Researchers in the discipline of Microwave Filters. The Filters are indispensable in microwave Communications.Band-Stop Filter is a circuit that allows most frequencies to pass, but blocks or attenuates a certain range or band of frequencies. It is also known as a 'band-elimination' filter or a 'band-rejection filter'. It is widely used in wireless communication systems. This book contains five units, starting initially with introduction to microwave filters, microstrip lines,filter designing methods and later on bandstop filters theory with various implementation methods with future scopes are discussed.