A display element is configured as follows in order to prolong the display
lifetime of an electro-optical element without inserting a resistance
element or lowering the numerical aperture due to a change in layout. The
display element includes an organic EL element, which is an
electro-optical element, a power source line electrode, a scanning signal
line electrode, a data signal line electrode, a common electrode, an
auxiliary capacitance, a current control TFT for controlling the current
flowing through the organic EL element, and a data voltage control TFT
for controlling the timing at which current flows through the organic EL
element. The conductive resistance of the current control TFT is set such
that 0.1.ltoreq..beta..ltoreq.7.0, where .beta.(=Vr/Vel) is a ratio of a
voltage Vr applied across the current control TFT to a voltage Vel
applied across the organic EL element. Thus, the speed of the temporal
change of the luminance of the organic EL element is slowed down, and the
display lifetime is prolonged.