Oven only works at max temp

Question

Hi, the gas oven in my apartment only works at maximum 
temperature. The oven will start at any temperature and will 
operate for approximately 5mins. After this time the oven will
turn itself off unless set at the maximum temperature (i.e. at
maximum temperature the oven will remain on)

What is wrong and how do I fix this issue?
I think my oven is a Haier Gas Range, but I am not certain.