Samsung Galaxy NX500 Camera User Manual (en)

Cleaning the camera
Camera lens and display
Use a brush to remove dust and wipe the lens gently with a soft cloth.  
If any dust remains, apply lens cleaning liquid to a piece of lens cleaning 
paper and wipe gently.
Image sensor
Depending on different shooting conditions, dust may appear in photos 
because the image sensor is exposed to the external environment. This 
problem is normal, and the exposure to dust occurs in everyday use 
of the camera. You can remove dust from the sensor by operating the 
sensor cleaning function. (p. 183) If dust remains after cleaning the sensor, 
contact a service center. Do not insert the blower into the opening of the 
lens mount.
Camera body
Wipe gently with a soft, dry cloth.
Never use benzene, thinners, or alcohol to clean the camera. These solutions can 
damage the camera or cause it to malfunction.
Maintaining the camera