A display apparatus of the present invention includes display sections and sensor circuit sections. At least two directly adjacent changeover zones are provided in the region of the boarding zone and enable horizontal displacement of the elevator cars between the elevator shafts. A sequence circuit generates a memory address, a latch selection signal, and a control signal at predetermined timings when a power is turned on. The cooling device includes a control device that is configured for detecting a temperature gradient from sensor values of the first temperature sensor and of the second temperature sensor and for adjusting the final control element depending on the detected temperature gradient.