A sample analyzer comprising: a liquid aspirating unit that includes an aspirating tube and an actuator for moving the aspirating tube in an up and down direction, and that is configured to aspirate a liquid for a sample analysis using the aspirating tube from a container; a liquid surface detector for detecting a liquid surface in the container; a memory for storing a liquid level information indicating a liquid level in the container based on a detection result by the liquid surface detector; and a controller for controlling a speed for lowering the aspirating tube with respect to the liquid surface in the container by the actuator based on the liquid level information stored in the memory, and controlling the liquid aspirating unit to aspirate the liquid from the container with the aspirating tube; characterised in that the controller is configured to execute a liquid surface detection of detecting the liquid surface in the container by the liquid surface detector prior to a lowering operation of the aspirating tube for aspirating the liquid if the liquid level information is not stored in the memory, and store a liquid level information of the container in the memory based on a detection result by the liquid surface detection; wherein the sample analyzer further comprises an operation mechanism for executing another operation for analyzing the sample, different from an operation for the liquid surface detection; wherein the controller is further configured to control the operation mechanism to execute at least one part of the other operation while executing the liquid surface detection with respect to the liquid in the container; wherein the operation mechanism is configured to execute, as the other operation, an operation of warming the sample. a liquid aspirating unit that includes an aspirating tube and an actuator for moving the aspirating tube in an up and down direction, and that is configured to aspirate a liquid for a sample analysis using the aspirating tube from a container; a liquid surface detector for detecting a liquid surface in the container; a memory for storing a liquid level information indicating a liquid level in the container based on a detection result by the liquid surface detector; and a controller for controlling a speed for lowering the aspirating tube with respect to the liquid surface in the container by the actuator based on the liquid level information stored in the memory, and controlling the liquid aspirating unit to aspirate the liquid from the container with the aspirating tube; characterised in that the controller is configured to execute a liquid surface detection of detecting the liquid surface in the container by the liquid surface detector prior to a lowering operation of the aspirating tube for aspirating the liquid if the liquid level information is not stored in the memory, and store a liquid level information of the container in the memory based on a detection result by the liquid surface detection; wherein the sample analyzer further comprises an operation mechanism for executing another operation for analyzing the sample, different from an operation for the liquid surface detection; wherein the controller is further configured to control the operation mechanism to execute at least one part of the other operation while executing the liquid surface detection with respect to the liquid in the container; wherein the operation mechanism is configured to execute, as the other operation, an operation of warming the sample.