Good Morning Vairo, 

Thank you for contacting the U of M Extension Service. 

You did not give me a lot of details about your tree. You might further inspect the trunk, branches and leaves for signs of further disease or insect damage. Please click on the following link from the U of M Extension Yard and Garden website about potential diseases of apple trees: https://apps.extension.umn.edu/garden/diagnose/plant/fruit/apple/leavesspots.html

This is the result of using "What's wrong with my plant?". All of the information on our website is research based. 

The disease on your tree may be apple scab. The information discusses what to do about it, if that is the disease. 

Good Luck!