Turbine blade and method for machining same

A turbine blade for a gas turbine, comprising:

• a blade root;
• and
• an aerodynamically curved blade leaf extending from the blade root, the blade leaf including:
• a leading edge;
• a trailing edge;
• a pressure-side blade wall and a suction-side blade wall each extending from the leading edge to the trailing edge so as to guide a working medium around the blade leaf;
• and
• a plurality of cooling-air outlet openings configured to emit cooling air routed through an inside of the blade leaf, each cooling-air outlet opening formed on the pressure-side blade wall so as to extend upstream from the trailing edge relative to a direction of flow of the working medium,
• wherein at least one cooling-air outlet opening of the plurality of cooling-air outlet openings includes a rectangular or trapezoidal shape with rounded corners,
• wherein at least one of the rounded corners on an upstream side and closest to the blade root, forms a relief notch which projects outward from the rectangular or trapezoidal shape and includes a rounded notch base.