An automatic analysis device, comprising; a probe configured to perform a dispensing operation including a suction process and a discharge process with respect to liquid; a syringe configured to generate a pressure change for dispensing liquid at the probe ; a flow path that connects the probe and the syringe with each other; a pressure sensor that measures the pressure change in the flow path at the time of liquid dispensing; a storage portion that stores a pressure change of time-series when reference fluid is discharged as a reference discharge pressure waveform; and a determination portion configured to determine whether or not there is an abnormality in the suction process of the sample from a relationship between • a value of o a difference or a o ratio between ∘ the reference discharge pressure waveform and ∘ a pressure waveform of a determination target at the time of discharge of liquid and • a normal range, characterized in that the storage portion is configured to store a relationship between a timing out of the normal range and an amount of air mixed in the liquid for each preset dispensing amount, and wherein the determination portion includes a function which estimates the amount of air mixed from said timing from when the pressure difference or ratio between the pressure waveform at the time of discharge of the liquid as the determination target and the reference pressure waveform once deviates from the determination range until it again falls within the determination range. a probe configured to perform a dispensing operation including a suction process and a discharge process with respect to liquid; a syringe configured to generate a pressure change for dispensing liquid at the probe ; a flow path that connects the probe and the syringe with each other; a pressure sensor that measures the pressure change in the flow path at the time of liquid dispensing; a storage portion that stores a pressure change of time-series when reference fluid is discharged as a reference discharge pressure waveform; and a determination portion configured to determine whether or not there is an abnormality in the suction process of the sample from a relationship between • a value of o a difference or a o ratio between ∘ the reference discharge pressure waveform and ∘ a pressure waveform of a determination target at the time of discharge of liquid and • a normal range, characterized in that the storage portion is configured to store a relationship between a timing out of the normal range and an amount of air mixed in the liquid for each preset dispensing amount, and • a value of o a difference or a o ratio between ∘ the reference discharge pressure waveform and ∘ a pressure waveform of a determination target at the time of discharge of liquid and o a difference or a o ratio between ∘ the reference discharge pressure waveform and ∘ a pressure waveform of a determination target at the time of discharge of liquid and • a normal range, wherein the determination portion includes a function which estimates the amount of air mixed from said timing from when the pressure difference or ratio between the pressure waveform at the time of discharge of the liquid as the determination target and the reference pressure waveform once deviates from the determination range until it again falls within the determination range. <EOS>