Ink having the optimum contact angle relative to a partition wall is selected for forming a pixel, based on the relationship with an inclination angle of the partition wall. The ink applied to the opening of the partition wall is dried to form the pixel such that an outer edge in contact with the partition wall has a thickness of at least 35% of the maximum height of the partition wall and a difference between the maximum thickness and the average thickness and a difference between the minimum thickness and the average thickness are not larger than 35% of the average thickness in an effective pixel area.