ductal carcinoma is characterized by a lump in the breast made up of cancerous cells surrounded by scar tissues caused by cancer. FT-IR microspectroscopy opens the chance for investigating in depth the subtle chemical chenges within the tissues. In this work,we have addressed the composition of invasive ductal carcinoma tissue by FT-IR microspectroscopy. This provides to investigate the in situ chemical composition of tissue at a scale of few microns. In this work we have addressed the composition of invasive ductal carcinoma tissue by FT-IR microspectroscopy. The most significant changes between cancerous and non-cancerous breast tissues occur at the phosphorylating and the DNA phosphodiester groups. This indicates that the phosphorylating processes usually occur in carcinomatous tissue sections.