For the past twenty years, invasive fungal infections have dramatically increased resulting in the high morbidity and mortality. The main reason of these infections is the development of invasive diagnostic and therapeutic technologies. Immunosuppression, neutropenia, broad-spectrum antibacterial agents, corticosteroids, chemotherapy, central intravascular catheter, total parenteral nutrition are the major risk factors of the invasive fungal infections. Most of these factors are very common for hospitalized patients. For example, patients with fungemia are more likely to die during hospitalization then those with bloodstream infection caused by nonfungal pathogens. Unfortunately, diagnosis and diagnostic methods of fungal infection are still difficult.