The king has no fever and a blood test showed a decrease in inflammation, it said, adding that an x-ray of his lungs showed no sign of inflammation.
It is the fourth health statement in over a week and follows a bulletin on Wednesday which said that the king had shown further improvement following a severe infection.
Doctors have stopped administering antibiotics to the king and will closely monitor his kidneys, the palace statement added.
The king has been treated for various ailments during a year-long hospitalization in the Thai capital.
The king was last seen in public on January 11.